ch 19 book questions (not finished)

describe the steps involved in the chain of infection

1. reservoir of infectious agent: suitable environment for the pathogen 2. portal of exit: coughing from your mouth or poop 3. transmission: infectious agent transmitted from reservoir it exited to new host 4. portal of entry: gaining access inside host 5. susceptible host: general health, age, gender, behavior, genetic background, immunity Infectious agent leaves their reservoir through a portal of exit and can be transmitted to a new host. If any link in this chain is broken, disease transmission is slowed or stopped

FO: pg 496-name one microbe that might be used as a weapon in bioterrorism

Bacillus anthracis

which of the following is an example of a fomite? a. table b. flea c. Staphylococcus aureus carrier d. water e. air

a

which of the following methods of disease transmission is the most difficult to control? a. airborne b. foodborne c. waterborne d. vector-borne e. direct person to person

a

name two typical sources of non-communicable diseases

a disease that does not spread from one host to another disease is often caused by individual's own normal flora or from an environmental reservoir

if you and your family all develop infectious diarrhea, the most likely portal of entry for the pathogen was the a. large intestine b. mouth c. skin d. respiratory tract e. nose

b

which of the following would be easiest to eradicate? a. a pathogen that is common in wild animals but sometimes infects humans b. a disease that occurs exclusively in humans, always resulting in obvious symptoms c. a mild disease of humans that often results in no obvious symptoms d. a pathogen found in marine sediments e. a pathogen that readily infects both wild animals and humans

b

which of the following common causes of healthcare associated infections is an environmental organism that grows readily in nutrient-poor solutions? a. Enterococcus b. Escherichia coli c. Pseudomonas aeruginosa d. Staphylococcus aureus

c

why are diseases with long incubation periods more likely to result in an epidemic?

depending on the microbe and the illness, an asymptomatic carrier in the incubation period might be shedding infectious microbes to his/her surroundings. In such a case, a longer incubation period would lead to a greater spread of the disease as the carrier comes into contact with more individuals while he/she is generally appearing to be healthy

all of the following are thought to contribute to the emergence of disease except a. advances in technology b. breakdown of public health infrastructure c. construction of dams d. mass distribution and importation of food e. widespread vaccination programs

e

what is the most common type of nosocomial infection? a. blood stream infection b. gastrointestinal infection c. pneumonia d. surgical wound infection e. urinary tract infection

e

which of the following statements is false? a. a disease with a long incubation period might spread extensively before an epidemic is recognized b. a person exposed to a low dose of a pathogen might not develop disease c. the young and the aged are more likely to develop certain diseases d. malnourished populations are more likely to develop certain diseases e. herd immunity occurs when a population does not engage in a given behavior, such as eating raw fish, that would otherwise increase their risk of disease

e

list the main portals of exit from the human body

eyes digestive tract respiratory tract broken skin genitourinary tract

name the most important control measure for preventing person-to-person transmission of a disease

hand washing

describe the conditions that may allow eradication of a disease

improved sanitation, reservoir and vector control, vaccination, and antibiotic treatment

explain the difference between incidence of a disease and prevalence of the disease

incidence measures occurrence of disease in a population prevalence measures existence of disease in a population

describe two ways in which infectious agents can be transmitted to a patient

indirect transmission-airborne (cough in the patient's room, etc. and the patient inhales the bacteria) direct transmission-healthcare personnel: direct contact with the patient (forget to wash hands, not wearing gloves, etc. after working with a different patient)

describe four reservoirs of infectious agents in healthcare settings and three mechanisms by which the agents can be transferred to patients

infectious agents -other patients -healthcare environment -healthcare workers -patient microbiota transferable to patients -direct transmission-healthcare personnel -fomite transmission-medical devices -airborne transmission

about 1500 malaria cases are reported in the US each year as a result of travel to countries where the disease is endemic

mb 478

On average, two new mosquito-borne diseases that infect humans are discovered every year

mb 483

people who take antacids or drugs that decrease production of stomach acid have increased risk of gastrointestinal infections

mb 485

the first case of HINI influenza in the pandemic of 2009 was traced to a 5 year old boy in Veracruz, Mexico

mb 486

Chlamydial infection is the most commonly reported sexually transmitted infection in the US, with over 1.4 million reported cases in 2012

mb 489

about 75% of emerging infectious diseases affecting humans are of animal origin

mb 492

explain how characteristics of a pathogen and a host can influence the epidemiology of a disease

pathogen: virulence: ability to cause disease dose: ID50 incubation period: lung incubation period can allow extensive spread host: immunity to pathogen health age gender religion and culture genetics

describe the role of infection control committees in preventing nosocomial infections

policies infection control committee -CDC has established healthcare infection control practices advisory committee (HICPAC)

explain why smallpox was successfully eradicated, but rabies probably never will be

smallpox was only found in humans; rabies is found in numerous animal reservoirs. we cannot reasonably eliminate rabies in all of the animal reservoirs that exist.

P: pg 495-know this well

standard precautions-protecting patients and health care personnel hand hygiene, personal protective equipment, respiratory hygiene/cough etiquette, patient placement, patient-care equipment and instruments/devices, care of the environment, textiles and laundry, safe injection practices, infection control practices for special lumbar puncture procedures, worker safety

why do influenza outbreaks in nursing homes typically have higher case-fatality rates than influence outbreaks in a college dormitory?

the older population has a weaker immune system

what is the epidemiological significance of people who have asymptomatic infections

these people may shed the organism intermittently or constantly for months, years, or even a lifetime they have no reason to consider themselves a reservoir